The present invention relates generally to an improved formulation for surface coating applications, particularly wherein the surfaces to be coated are in frequent contact with water, and additional surface roughness is required to increase frictional and anti-slip characteristics of the surface. The surface coating formulations of the present invention are particularly adapted for providing uniform surface roughness or coarseness which enhances frictional, and particularly anti-slip characteristics on treated surfaces.
In many situations, it is desirable, if not necessary, to provide a surface with enhanced frictional properties, particularly a surface which is roughened sufficiently to provide the desired frictional and anti-slip characteristics. One typical application is for decks of surfboards, as well as on surfaces of wind surfing equipment. The recent increase in popularity of these items as sporting equipment has created an unusual need for an anti-slip coating which is effective under water-wet conditions, including a relatively wide range of temperatures. In addition to use in combination with sporting equipment, this material may also be used around swimming pools, shower stalls, bathtubs, and other areas where it is desirable to have anti-slip characteristics in surfaces subject to becoming wet with water.
Various types of anti-slip products have been designed in the past, and frequently in the form of a laminate or thin flexible decal which may be applied to a surface by pressure-sensitive adhesive or the like. The present formulation, being an organic solvent coating dispersion, may be applied by either brushing, spraying, or other conventional techniques to the entire area desired for the coating. The formulation, because of the selection of components, is such that spraying may be achieved by air-pressure systems, or alternatively by aerosol packaging.
One unusual feature of this invention is the high degree of anti-slip characteristics and properties which are developed in the exposed surface, particularly under water-wet conditions. While the specific reason for achieving this increase in friction and anti-slip properties is unknown, it is believed to have been achieved by the combination of an elastomeric vehicle with high-strength glass bubbles or spheres. High-strength glass bubbles of generally spherical form are described in U.S. Pat. No. 3,365,315, and are, of course, commercially available. The vehicle, including the elastomeric components, provides good adhesion to the surface to which it is being applied, as well as a proper balance and maintenance of cohesive properties. Specifically, the formulations of the present invention provide an appropriate adjustment of adhesive strength to cohesive strength in the finished cured coating. Thus, the formulations of the present invention have been found to be resistant to stripping or peeling, and have been found to achieve the property of removal from the surface only upon tearing.
In connection with surfboard enthusiasts, there are demands for various types of anti-slip coating formulations. In certain applications, and for certain such enthusiasts, it is deemed desirable to have a transparent coating which makes it possible to exhibit any unusual feature of the natural surface or any unique or colorful design of the artwork available on the surfboard substrate. In others, there may be a need or desire for applying a certain type of coating as well as coatings which fluoresce or otherwise glow in the presence of ultraviolet rays of the sun. With each of these various features in mind, the coating formulations of the present invention lend themselves to modification so as to achieve such results and/or properties, while still permitting application by spraying, including both air-pressure and aerosol spraying. The components present in the formulations of the present invention are non-clogging, this being due to the utilization of the glass bubbles which are small in size and substantially spherical in configuration.
In addition to use of these coatings on surfaces which are frequently subject to wetting, the materials have application for use on surfaces of elastomeric and plastic foams, especially polyethylene and polyurethane foams. In particular, closed foams are used for a variety of purposes and as such, do not permit air to pass readily from one side to the other. In connection with certain facilities used for athletic purposes, such as exercise and wrestling mats, these materials have a frequent need of covering or coating with an elastomeric seal-coat with anti-slip properties. It is a desirable feature of any such seal-coat to utilize a coating which bridges the surface pores of the foam without providing significant penetration of the pore structure of the foam. In this fashion, saturation of the pores of the foam with the seal-coat is avoided. Such a feature is desirable in that saturation would in certain instances detract from the padding effect and would further increase the weight of the foam structure, thus providing for added weight, less resiliency or bounce, and less absorption of impact.